1. Field of the Invention
The invention relates to a display device. More particularly, the invention provides a display device that can automatically adjust the display brightness via a disposition of photo-sensors so as to achieve the function of feedback brightness.
2. Description of the Related Art
A liquid crystal display (LCD) panel provides a planar display that is widely used in portable electronic equipments such as portable computers, personal digital assistants (PDA) and recently developed web pads. The principal advantage of the LCD panel lies in a substantial reduction of its size and weight and, furthermore, since the LCD panel has no electron accelerator therewithin, the screen thickness are therefore considerably reduced in comparison with traditional CRT display devices.
Although the numerous advantages described above, LCD panels also have some inconveniences. Well known downsides hence include an inferior image quality, including, for example, the inferior display contrast and narrower angle of view. Regarding some aspects, a LCD device therefore still does not provide the same quality comparing with CRT counterparts. More particularly, the worst scenario for the inferiority of the display contrast of the LCD device is if the LCD device is operated in somewhere with relatively high brightness. As a result, the display quality therefore greatly relies upon the brightness of the environment. Although some LCD devices are provided with the automatic adjustment of light brightness and contrast, these types of adjustments known in the prior arts are however in accordance with the displayed frame and further require a compulsory activation from the user. Therefore, in order to obtain an optimal display, the user usually has to adjust the display parameters of the LCD display device. When the brightness of the environment increases, the display contrast or brightness has to be adjusted accordingly. The same rule is applicable to the situation while the brightness of the environment lowers. For users, the above mentioned adjustments always lead to some inconveniences.
It is therefore a principal object of the invention to provide a brightness feedback display device that can automatically adjust the display brightness of the display device according to the variation of the environment brightness of the display device.
It is another object of the invention to provide a brightness feedback display device that can provide an optimal display brightness that matches with the environment conditions by means of a feedback brightness sensing.
Furthermore, it is another object of the invention to provide a brightness feedback display device that can prevent excessive display brightness or darkness of the display device with respect to the brightness of the environment, thereby reducing the power consumption and protecting the user""s eyes.
To accomplish the above and other objectives, a brightness feedback display device comprises a display panel, a plurality of first photo-sensors, a plurality of first converters, a light-guiding element, a feedback sensing unit and a microprocessor. The first photo-sensors respectively sense environmental brightness variations of the display device, and respectively output corresponding sensing signals. The first converters are respectively connected to the first photo-sensors and convert the respective sensing signals to a plurality of corresponding first digital reference signals. The light-guiding element receives and transmits the light emitted from the display panel. The feedback sensing unit further includes a second photo-sensor and a second converter. The second photo-sensor senses the light variation from the light-guiding element, and then the second converter converts the sensed light variation to generate a second digital reference signal. The microprocessor controls the brightness of the display panel according to the variation of the first and second digital reference signals.
To provide a further understanding of the invention, the following detailed description illustrates embodiments and examples of the invention, this detailed description being provided only for illustration of the invention.